Display element and electronic device

ABSTRACT

There is provided a display element, including: a display region including pixels arranged in a two-dimensional form, each of the pixels including a plurality of sub pixels. In each pixel, a height of a light reflecting portion with respect to a light emitting portion is adjusted for each sub pixel.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of application Ser. No.16/955,917, filed Jun. 19, 2020, which is a 371 National Stage Entry ofInternational Application No.: PCT/JP2018/047187, filed on Dec. 21,2018, which claims the benefit of Japanese Priority Patent ApplicationJP 2017-248697 filed on Dec. 26, 2017, the entire contents of which areincorporated herein by reference.

TECHNICAL FIELD

The present technology relates to a display element and an electronicdevice, and more particularly, to a display element and an electronicdevice which are capable of improving luminance of pixels.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Priority PatentApplication JP 2017-248697 filed Dec. 26, 2017, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND ART

In recent years, as a light emitting element which emits light by itselfwhen a voltage is applied, a light emission type display element such asan organic EL display element using an organic light emitting diode(OLED) in which a phenomenon called organic electroluminescence (organicEL) is applied has been developed.

In the organic EL display element, if light extraction efficiency ispoor, an actual light emission amount in the organic EL element is notused effectively, leading to a loss in terms of power consumption or thelike, and thus there is a demand for a technique of extracting lightefficiently.

As a technique for improving light extraction efficiency, for example, atechnique disclosed in PTL 1 is known. A technique related to an anodereflector structure which reflects some of light propagated on a membersurface using a difference in a refractive index between members isdisclosed in PTL 1.

CITATION LIST Patent Literature [PTL 1]

-   JP 2013-191533A

SUMMARY OF INVENTION Technical Problem

In the organic EL display element, a method of increasing a lightemitting area by increasing a size of a specific pixel in order toimprove luminance of each pixel can be used, but in a case in which sucha method is employed, since a pixel pitch changes, it is difficult toachieve high definition. For this reason, there is a demand for atechnique of improving luminance of pixels more appropriately.

It is desirable to make it possible to improve the luminance of thepixels.

Solution to Problem

The present technology is defined by the claims.

Advantageous Effects of Invention

According to an embodiment of the present technology, the luminance ofpixels can be improved.

Further, the effect described here is not necessarily limiting, and anyeffect described in the present disclosure may be included.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating an example of a configuration ofone embodiment of a display element to which the present technology isapplied.

FIG. 2 is a circuit diagram illustrating an example of a configurationof a pixel drive circuit.

FIG. 3 is a plan view illustrating an example of a configuration of adisplay region.

FIG. 4 is a main part cross-sectional view illustrating a part of astructure of a pixel according to a related art.

FIG. 5 is a main part cross-sectional view illustrating a part of astructure of a pixel according to a first embodiment.

FIG. 6 is a main part cross-sectional view illustrating a part of astructure of a pixel according to a second embodiment.

FIG. 7 is a main part cross-sectional view illustrating a part of astructure of a pixel according to a third embodiment.

FIGS. 8A and 8B each show a main part cross-sectional view illustratinga part of a structure of a pixel according to variants of a fourthembodiment.

FIGS. 9A, 9B and 9C each show a main part cross-sectional viewillustrating a part of a structure of a pixel according to variants of afifth embodiment.

FIGS. 10A and 10B each show a main part cross-sectional viewillustrating a part of a structure of a pixel according to variants of asixth embodiment.

FIG. 11 shows a main part cross-sectional view illustrating a part of astructure of a bottom emission sub pixel 100 according to a seventhembodiment.

FIGS. 12A and 12B each show a main part cross-sectional viewillustrating a part of a structure of a pixel according to variants ofan eighth embodiment.

FIG. 13 is a conceptual diagram for describing reflection of light by areflector.

FIG. 14 is a diagram illustrating a relation between a distance to aninclined surface of a reflector and a height of the reflector at whichtotal reflection is performed.

FIG. 15 is a conceptual diagram for describing the reflection of lightby a reflector.

FIG. 16 is a table illustrating a change in a height of a reflectorsatisfying a total reflection condition in a case in which a reflectorangle is changed.

FIG. 17 is a diagram illustrating an example of a structure of areflector satisfying a predetermined total reflection condition.

FIG. 18 is a diagram for describing a flow of a first example of a pixelmanufacturing process according to an embodiment of the presenttechnology.

FIG. 19 is a diagram for describing a flow of a first example of a pixelmanufacturing process according to an embodiment of the presenttechnology.

FIG. 20 is a diagram for describing a flow of a first example of a pixelmanufacturing process according to an embodiment of the presenttechnology.

FIG. 21 is a diagram for describing a flow of a first example of a pixelmanufacturing process according to an embodiment of the presenttechnology.

FIG. 22 is a diagram for describing a flow of a first example of a pixelmanufacturing process according to an embodiment of the presenttechnology.

FIG. 23 is a diagram for describing a flow of a second example of apixel manufacturing process according to an embodiment of the presenttechnology.

FIG. 24 is a diagram for describing a flow of a second example of apixel manufacturing process according to an embodiment of the presenttechnology.

FIG. 25 is a diagram for describing a flow of a second example of apixel manufacturing process according to an embodiment of the presenttechnology.

FIG. 26 is a diagram for describing a flow of a second example of apixel manufacturing process according to an embodiment of the presenttechnology.

FIG. 27 is a diagram for describing a flow of a second example of apixel manufacturing process according to an embodiment of the presenttechnology.

FIG. 28 is a diagram illustrating an example of an external appearanceof a single-lens reflex camera as an electronic device to which adisplay element to which an embodiment of the present technology isapplied is applied.

FIG. 29 is a diagram illustrating an example of an external appearanceof a head mounted display as an electronic device to which a displayelement to which an embodiment of the present technology is applied isapplied.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present technology will be describedwith reference to the appended drawings. Further, the description willproceed in the following order.

1. Embodiments of Present Technology

2. Modified example3. Example of electronic device

1. Embodiments of Present Technology (Configuration Example of DisplayElement)

FIG. 1 is a block diagram illustrating an example of a configuration ofone embodiment of a display element to which the present technology isapplied.

In FIG. 1 , a display element 1 is a light emission type display element(display device) such as an organic EL display element using, forexample, an organic light emitting diode (OLED).

As illustrated in FIG. 1 , in the display element 1, a plurality ofpixels (sub pixels 100R, 100W, 100G, and 100B) are two-dimensionallyarranged on a substrate 11 made of, for example, glass, a silicon wafer,or a resin, so that a display region 23 is formed. Further, a signalline drive circuit 21 and a scan line drive circuit 22 which are driversfor video display are formed on the periphery of the display region 23.

A pixel drive circuit 33 is formed in the display region 23. FIG. 2illustrates an example of a configuration of the pixel drive circuit 33.

As illustrated in FIG. 2 , the pixel drive circuit 33 is an active typedrive circuit including a drive transistor Tr1, a write transistor Tr2,a capacitor (retention capacitor) Cs therebetween, and organic lightemitting elements 101 (101R, 101W, 101G, and 101B) connected to thedrive transistor Tr1 in series between a first power line (Vcc) and asecond power line (GND).

In the pixel drive circuit 33, a plurality of signal lines 31 arearranged in a column direction, and a plurality of scan lines 32 arearranged in a row direction. Crossing points of the signal lines 31 andthe scan lines 32 correspond to the sub pixels 100R, 100W, 100G, and100B including any one of the organic light emitting elements 101R,101W, 101G, 101B.

Each signal line 31 is connected to the signal line drive circuit 21,and an image signal is supplied from the signal line drive circuit 21 toa source electrode of the write transistor Tr2 via the signal line 31.Each scan line 32 is connected to the scan line drive circuit 22, and ascan signal is sequentially supplied from the scan line drive circuit 22to a gate electrode of the write transistor Tr2 via the scan line 32.

FIG. 3 illustrates an example of the plane configuration of the displayregion 23. In FIG. 3 , the display the sub pixel 100R that generates red(R) light, the sub pixel 100W that generates white (W) light, the subpixel 100G that generates green (G) light, and the sub pixel 100B thatgenerates blue (B) light are sequentially formed in the display region23 in a two-dimensional form as a whole.

Further, a combination of the adjacent sub pixels 100R, 100W, 100G, and100B (the sub pixels) constitutes one pixel 10. In other words, aplurality of pixels 10 are arranged in the display region 23 in atwo-dimensional form (in a matrix form), and each pixel 10 isconstituted by four sub pixels 100 of red (R), white (W), green (G), andblue (B). In other words, in the display region 23, the pixels 10arranged in the two-dimensional form are referred to as a WRGB pixel.

(Structure of Pixel)

In the organic EL display element, in order to improve the luminance ofrespective sub pixels constituting a pixel, it is possible to cope withit by changing a size of a sub pixel. However, in a case in which themethod of increasing the light emitting area by increasing a size of aspecific sub pixel among pixels is employed, since the pixel pitch ischanged, it is difficult to achieve high definition.

Specifically, as illustrated in FIG. 4 , in a pixel 90 including foursub pixels 900, a structure in which a light emitting area of a lightemitting portion in a sub pixel 900W among the four sub pixels 900 isincreased in order to improve luminance of the sub pixel 900W isassumed.

In this structure, since the light emitting area is increased only inthe sub pixel 900W, the pixel pitch of the sub pixel 900W is differentfrom the pixel pitches of the other sub pixels 900R, 900G, and 900B.Further, as described above, if the pixel pitch is changed for each subpixel 900, it is difficult to achieve high definition.

In this regard, in the present technology, it is possible to adjust theluminance of each sub pixel 100 without changing the pixel pitch byadjusting a height of a light reflecting portion (reflector) withrespect to the light emitting portion for each sub pixel 100constituting the pixel 10. Hereinafter, structures of the pixels 10 ofthe first to third embodiments will be described in order as a structureof a pixel to which an embodiment of the present technology is applied.

(First Example of Structure of Pixel)

FIG. 5 is a main part cross-sectional view illustrating a part of astructure of a pixel according to a first embodiment. A structure of apixel 10 according to the first embodiment will be described below withreference to the main part cross-sectional view.

In FIG. 5 , the pixel 10 of the first embodiment includes four subpixels, that is, a sub pixel 100R that emits red (R) light, a sub pixel100W that emits white (W) light, a sub pixel 100G that emits green (G)light, and a sub pixel 100B that emits blue (B) light.

Further, the sub pixel 100R includes an organic light emitting element101R. Similarly, the sub pixels 100W, 100G, and 100B include the organiclight emitting elements 101W, 101G, and 101B, respectively.

The organic light emitting element 101R is a light emitting portionincluding an organic layer including a light emitting layer, and anelectrode. In the organic light emitting element 101R, the organic layerhas a structure sandwiched between an anode electrode and a cathodeelectrode, but only an anode electrode 121R is illustrated in FIG. 5 .Further, an opening portion in which the anode electrode 121R is exposedspecifies the light emitting portion.

Here, the organic layer includes a light emitting layer made of anorganic light emitting material, but specifically, for example, theorganic layer may have a stacking structure of a hole transport layer, alight emitting layer, and an electron transport layer, a stackingstructure of a hole transport layer and a light emitting layer doublingas an electron transport layer, a stacking structure of a hole injectionlayer, a hole transport layer, a light emitting layer, an electrontransport layer, and an electron injection layer, or the like. Forexample, it is desirable that this organic light emitting element 101Remploy a structure that emits white light.

Further, in the sub pixel 100R, a color filter 131R by which transmittedlight becomes a red (R) region is formed for the organic light emittingelement 101R, and the sub pixel 100R generates red (R) light throughsuch a combination.

Similarly to the organic light emitting element 101R, the organic lightemitting element 101W is a light emitting portion including an organiclayer and an electrode (including an anode electrode 121W). No colorfilter is formed for the organic light emitting element 101W, and thesub pixel 100W generates white (W) light.

Similarly to the organic light emitting element 101R, the organic lightemitting element 101G is a light emitting portion including an organiclayer and an electrode (including an anode electrode 121G). A colorfilter 131G by which transmitted light becomes a green (G) region isformed for the organic light emitting element 101G, and the sub pixel100G generates green (G) light through such a combination.

Similarly to the organic light emitting element 101R, the organic lightemitting element 101B is a light emitting portion including an organiclayer and an electrode (including an anode electrode 121B). A colorfilter 131B by which transmitted light becomes a blue (B) region isformed for the organic light emitting element 101B, and the sub pixel100B generates blue (B) light through such a combination.

Further, in the pixel 10 of the first embodiment, a reflector (lightreflecting portion) is formed to improve the light extractionefficiency.

Here, the reflector includes a first member that reflects light from theorganic light emitting element toward a display surface side on a firstsubstrate and a second member which fills a space between a secondsubstrate arranged opposite to the first substrate and a lightreflection structure and has a refractive index different from arefractive index of the first member, and the reflector reflects lightpropagating through the second member on the surface of the firstmember, so that the light extraction efficiency can be improved.

As illustrated in FIG. 5 , in the pixel 10 of the first embodiment, areflector 112 is formed on a surface of a first member 111 configured asa light reflecting layer (reflector structure). Further, the firstmember 111 (in this embodiment and in the subsequently describedembodiments) can be formed using a material such as, for example, SiO₂and/or P—SiO.

Further, although not illustrated in FIG. 4 , in the pixel 10 of thefirst embodiment, a second member (for example, a second member 151 inFIG. 22 to be described later) that propagates light from each organiclight emitting element 101 and emits the light toward the outside isformed, and the first member 111 is formed to fill a space between thesecond members. In other words, the light reflecting layer (reflectorstructure) is formed by the first member 111 and the second member (forexample, the second member 151 in FIG. 22 to be described later).

As illustrated in FIG. 5 , in the pixel 10 of the first embodiment, thefour sub pixels including the sub pixel 100R, the sub pixel 100W, thesub pixel 100G, and the sub pixel 100B differ in the height of thereflector 112 (the height of the inclined surface of the first member111).

Here, in the first member 111, a side wall of the opening portion inwhich the anode electrode 121 is exposed is inclined at a predeterminedinclination angle (reflector angle), and the inclined surface (surface)forms the reflector 112. Hereinafter, the height of the inclined surfacein the stacking direction is also referred to as an “inclined surfaceheight” of the reflector 112.

In other words, in the pixel 10 of the first embodiment, in a case inwhich the inclined surface heights of the reflectors 112 in therespective sub pixels 100 are compared, for example, a relationillustrated in the following Formula (1) can be obtained.

Inclined surface height of reflector 112W>inclined surface height ofreflector 112G>inclined surface height of reflector 112R>inclinedsurface height of reflector 112B  (1)

Here, in Formula (1), the inclined surface height of the reflector 112Wcorresponds to the height of the inclined surface of the first member111 in the sub pixel 100W. Similarly, the inclined surface heights ofthe reflectors 112G, 112R, and 112B correspond to the heights of theinclined surfaces of the first members 111 in the sub pixels 100G, 100R,and 100B.

As described above, in the pixel 10 of the first embodiment, luminanceof a specific sub pixel 100 is increased such that the four sub pixels100 are formed to differ in the inclined surface height of the reflector112, and the respective sub pixels 100 differ in luminance. Inparticular, when the inclined surface height of the reflector 112W ofthe sub pixel 100W is high, a region in which light from the organiclight emitting element 101W (the anode electrode 121W) undergoes totalreflection increases, and thus the luminance of the sub pixel 100W isimproved, whereby the luminance of the entire pixel 10 can be improved.

Further, in the pixel 10 of the first embodiment, since the region thatreflects light, that is, the inclined surface height of the reflector112 is changed without changing the light emitting area or the pitcharrangement in each sub pixel 100, the respective sub pixels 100 differin luminance, and thus it is possible to easily achieve high definition.

As described above, in the pixel 10 of the first embodiment, theinclined surface height of the reflector 112 with respect to the organiclight emitting element 101 (the anode electrode 121) serving as thelight emitting portion is adjusted for each sub pixel 100, so that theinclined surface heights of the reflector 112R, the reflector 112W, thereflector 112G, and the reflector 112B are different. Accordingly, inthe pixel 10 of the first embodiment, it is possible not only to improvethe light extraction efficiency by the light reflecting layer but alsoto improve the luminance of the specific sub pixel 100 by causing eachsub pixel 100 to have different luminance.

Further, in FIG. 5 , the example in which the inclined surface height ofthe reflector 112W is highest, and the inclined surface height decreasein the order of the reflector 112G, the reflector 112R, and thereflector 112B as indicated in Formula (1) has been described, but therelation indicated in Formula (1) is an example, and the order of theinclined surface heights is arbitrary as long as the inclined surfaceheights of the reflectors 112R, 112W, 112G, and 112B are different fromone another.

For example, in a case in which the respective sub pixels 100 in thepixel 10 differ in lifespan, since it is possible to reduce an appliedcurrent density by improving the luminance of the sub pixel 100, it ispossible to perform an adjustment so that the respective sub pixels 100have the same lifespan deterioration. In a case in which such anadjustment is performed, the inclined surface height of the reflector112 can be adjusted for each sub pixel 100 so that, for example, arelation indicated in the following Formula (1)′ is satisfied.

Inclined surface height of reflector 112B>inclined surface height ofreflector 112W>inclined surface height of reflector 112G>inclinedsurface height of reflector 112R  1)′

Further, in FIG. 5 , the sub pixels 100 constituting the pixel 10 arearranged in the order of the sub pixels 100R, 100W, 100G, and 100B fromthe left side to the right side in FIG. 5 , but the arrangement order ofthe sub pixels 100 is arbitrary. Further, in addition to a case in whichthe inclined surface height of the reflector 112 is a uniform heightlike the reflector 112W of the sub pixel 100W as illustrated in FIG. 5 ,a case in which the inclined surface height of the reflector 112 is notuniform is assumed, but in this case, for example, it is preferable toadjust an average value or the like of the inclined surface height ofthe reflector 112 for each sub pixel 100.

(Second Example of Structure of Pixel)

FIG. 6 is a main part cross-sectional view illustrating a part of astructure of a pixel according to a second embodiment. A structure of apixel 10 according to the second embodiment will be described below withreference to the main part cross-sectional view.

As illustrated in FIG. 6 , in a pixel 10 of a second embodiment, amongthe four sub pixels 100 including the sub pixel 100R, the sub pixel100W, the sub pixel 100G, and the sub pixel 100B, an inclined surfaceheight of a reflector 112 of a specific sub pixel 100 is different.

In other words, in the pixel 10 of the second embodiment (FIG. 6 ), aninclined surface height of a reflector 112 of a specific sub pixel 100among the four sub pixels 100 is changed without changing the inclinedsurface height of the reflector 112 for all of the four sub pixels 100as compared with the pixel 10 of the first embodiment (FIG. 5 )described above.

Specifically, in FIG. 6 , the inclined surface height of the reflector112W only in the sub pixel 100W is changed to be higher than theinclined surface heights of the reflectors 112R, 112G, and 112B of theother sub pixels 100R, 100G, and 100B.

In other words, in the pixel 10 of the second embodiment, in a case inwhich the inclined surface heights of the reflectors 112 in therespective sub pixels 100 are compared, for example, a relationillustrated in the following Formula (2) can be obtained.

Inclined surface height of reflector 112W>inclined surface height ofreflector 112R=inclined surface height of reflector 112G=inclinedsurface height of reflector 112B  (2)

Here, in Formula (2), the inclined surface height of the reflector 112Wcorresponds to the height of the inclined surface of the first member111 in the sub pixel 100W. Similarly, the inclined surface heights ofthe reflectors 112R, 112G, and 112B correspond to the heights of theinclined surfaces of the first members 111 in the sub pixels 100R, 100G,and 100B.

As described above, in the pixel 10 of the second embodiment, luminanceof a specific sub pixel 100 can be increased such that the specific subpixel 100 among the four sub pixels 100 is formed to differ in theinclined surface height of the reflector 112, and the respective subpixels 100 differ in luminance. For example, when the inclined surfaceheight of only the reflector 112W of the sub pixel 100W is high, aregion in which light from the organic light emitting element 101W (theanode electrode 121W) undergoes total reflection increases, and thus theluminance of the sub pixel 100W is improved, whereby the luminance ofthe entire pixel 10 can be improved.

Further, in the pixel 10 of the second embodiment, since the inclinedsurface height of the reflector 112 is changed without changing thelight emitting area or the pitch arrangement of each sub pixel 100, eachsub pixel 100 has different luminance, and thus it is possible to easilyachieve high definition.

As described above, in the pixel 10 of the second embodiment, theinclined surface height of the reflector 112 with respect to the organiclight emitting element 101 (the anode electrode 121) serving as thelight emitting portion is adjusted for each sub pixel 100 so that onlythe inclined surface height of the reflector 112 of the specific subpixel 100 is different from the inclined surface heights of thereflectors 112 of the other sub pixels 100. Accordingly, in the pixel 10of the second embodiment, it is possible not only to improve the lightextraction efficiency by the light reflecting layer but also to improvethe luminance of the specific sub pixel 100 by causing each sub pixel100 to have different luminance.

Further, in FIG. 6 , the example in which the inclined surface height ofthe reflector 112W is highest, and the inclined surface heights of theother reflectors, that is, the reflector 112G, the reflector 112R, andthe reflector 112B are equal as indicated in Formula (2) has beendescribed, but the relation indicated in Formula (2) is an example, andthe reflector 112 whose inclined surface height is changed is arbitraryas long as the inclined surface height of the reflector 112 of thespecific sub pixel 110 is different from the inclined surface heights ofthe other sub pixels 100.

Here, in a case in which the respective sub pixels 100 in the pixel 10differ in lifespan, it is possible to perform an adjustment so that therespective sub pixels 100 have the same lifespan deterioration bychanging the luminance for each sub pixel 100 as described above, butthe inclined surface height of the reflector 112G of the specific subpixel 100G can be adjusted so that, for example, a relation indicated inthe following Formula (2)′ is satisfied.

Inclined surface height of reflector 112B>inclined surface height ofreflector 112W=inclined surface height of reflector 112G=inclinedsurface height of reflector 112R  (2)′

Further, the example in which the inclined surface height of thereflector 112 of one sub pixel 100 as the specific sub pixel 100 ischanged has been described, but the number of specific sub pixels 100may be two or more, for example, the inclined surface heights of thereflectors 112W and 112B of the sub pixels 100W and 100B may be changed.

(Third Example of Structure of Pixel)

FIG. 7 is a main part cross-sectional view illustrating a part of astructure of a pixel according to a third embodiment. A structure of apixel 10 according to the third embodiment will be described below withreference to the main part cross-sectional view.

As illustrated in FIG. 7 , in a pixel 10 of a third embodiment, aposition of an anode electrode 121 of an organic light emitting element101 included in a specific sub pixel 100 among the four sub pixels 100including the sub pixel 100R, the sub pixel 100W, the sub pixel 100G,and the sub pixel 100B is adjusted.

In other words, in the pixel 10 of the third embodiment (FIG. 7 ), theposition of the anode electrode 121 of the organic light emittingelement 101 (the position in the stacking direction) is adjusted withoutadjusting the inclined surface height (the height in the stackingdirection) of the reflector 112 in the sub pixel 100 as compared withthe pixel 10 of the first embodiment (FIG. 5 ) described above and thepixel 10 of the second embodiment (FIG. 6 ).

As described above, the inclined surface height of the reflector 112with respect to the organic light emitting element 101 (the anodeelectrode 121) serving as the light emitting portion can be adjusted foreach sub pixel 100 by adjusting the position of the organic lightemitting element 101 (the anode electrode 121). Accordingly, it ispossible to cause the inclined surface height of the reflector 112 ofthe specific sub pixel 100 to be different from the inclined surfaceheights of the reflectors 112 of the other sub pixels 100.

Specifically, in FIG. 7 , only the anode electrode 121W of the organiclight emitting element 101W in the sub pixel 100W is formed with a largedepth in the stacking direction, and thus the inclined surface height ofthe reflector 112W of the sub pixel 100W is higher than the inclinedsurface heights of the reflectors 112R, 112G, and 112B of the sub pixels100R, 100G, and 100B.

In other words, in the third embodiment, in a case in which the inclinedsurface heights of the reflectors 112 in the respective sub pixels 100are compared, for example, a relation similar to that of Formula (2)described above is obtained.

As described above, in the pixel 10 of the third embodiment, theposition of the anode electrode 121 of the organic light emittingelement 101 of the specific sub pixel 100 among the four sub pixels 100is adjusted so that the inclined surface height of the reflector 112 ofthe specific sub pixel 100 is different, and thus it is possible tocause the respective sub pixels 100 to have different luminances, and itis possible to increase the luminance of the specific sub pixel 100accordingly.

For example, since the position of the anode electrode 121W of theorganic light emitting element 101W of the sub pixel 100W is adjusted sothat only the reflector 112W of the sub pixel 100W have a higherinclined surface height, the luminance of the sub pixel 100W isimproved, and the luminance of the entire pixel 10 can be improvedaccordingly.

Further, in the pixel 10 of the third embodiment, since the position ofthe anode electrode 121 of the organic light emitting element 101 isadjusted without changing the light emitting area or the pitcharrangement of each sub pixel 100, each sub pixel 100 has differentluminance, and thus it is possible to easily achieve high definition.

As described above, in the pixel 10 of the third embodiment, theinclined surface height of the reflector 112 with respect to the anodeelectrode 121 of the organic light emitting element 101 serving as thelight emitting portion 101 is adjusted for each sub pixel 100 byadjusting the position of the anode electrode 121 side of the specificsub pixel 100, and thus only the inclined surface height of thereflector 112 of the specific sub pixel 100 is different from theinclined surface heights of the reflectors 112 of the other sub pixels100. Accordingly, in the pixel 10 of the third embodiment, it ispossible not only to improve the light extraction efficiency by thelight reflecting layer but also to improve the luminance of the specificsub pixel 100 by causing each sub pixel 100 to have different luminance.

Further, in FIG. 7 , the example in which the inclined surface height ofthe reflector 112W is highest, and the inclined surface heights of theother reflectors, that is, the reflector 112G, the reflector 112R, andthe reflector 112B are equal so that the relation similar to that inFormula (2) is obtained has been described, but the relation is anexample, and the sub pixel 100 in which the position of the anodeelectrode 121 side is changed is arbitrary as long as the inclinedsurface height of the reflector 112 of the specific sub pixel 110 isdifferent from the inclined surface heights of the other sub pixels 100.

Further, the example in which the position of the anode electrode 121side of one sub pixel 100 as the specific sub pixel 100 is adjusted hasbeen presented here, but, for example, the number of specific sub pixels100 may be two or more, for example, the positions of the anodeelectrodes 121W and 121B side of the sub pixels 100W and 100B may beadjusted. Further, the position of the anode electrode 121 side may beadjusted for each sub pixel 100 in the pixel 10 so that, for example,the relation of Formula (1) described above is satisfied.

(Fourth Example of Structure of Pixel)

FIGS. 8A and 8B each show a main part cross-sectional view illustratinga part of a structure of a pixel according to variants of a fourthembodiment. A structure of a pixel 10 according to the fourth embodimentwill be described below with reference to these main partcross-sectional views.

As illustrated in FIG. 8A, in a pixel 10 of a first variant of thefourth embodiment, the first member 111 comprises a first (lower)portion 111A and a second (upper) portion 111B. The lower portion 111Acomprises the light emitting elements 101R, 101B, 101G and 101W of eachsub pixel 100R, 100B, 100G and 100W and the upper portion 111B comprisesthe reflector 112R, 112B, 112G and 112W of each sub pixel 100R, 100B,100G and 100W. The upper and lower portions 111A and 111B are separatedby a gap 800. The gap 800 comprises the color filters 131R, 131B and131G of each sub pixel 100R, 100B and 100G (the sub pixel 100W does nothave a color filter).

The inclined surface height of the reflector of one of the sub pixels(reflector 112B of sub pixel 100B, in this example) is higher than theinclined surface heights of the reflectors of the other sub pixels(reflectors 112R, 112G and 112W of sub pixels 100R, 100G and 100W, inthis example). In other words, in a case in which the inclined surfaceheights of the reflectors 112 in the respective sub pixels 100 arecompared, for example, a relation according to Formula (2)′ is obtained.

In the pixel 10 of FIG. 8A, the luminance of a specific sub pixel 100 isincreased by differing the inclined surface height of the reflector 112of the specific sub pixel 100 among the four sub pixels 100. Forexample, when the inclined surface height of the reflector 112B of thesub pixel 100B is higher than that of the other sub pixels (as shown inFIG. 8A), a region in which light from the organic light emittingelement 101B undergoes total reflection increases, and thus theluminance of the sub pixel 100B relative to that of the other sub pixelsis improved. Further, in the pixel 10 of FIG. 8A, since the inclinedsurface height of the reflector 112 is changed without changing thelight emitting area or the pitch arrangement of each sub pixel 100, itis possible to easily achieve high definition.

As described above, in the pixel 10 of FIG. 8A, the inclined surfaceheight of the reflector 112 with respect to the organic light emittingelement 101 serving as the light emitting portion is determined for eachsub pixel 100 so that only the inclined surface height of the reflector112 of the specific sub pixel 100 is different from the inclined surfaceheights of the reflectors 112 of the other sub pixels 100. Accordingly,in the pixel 10 of FIG. 8A, it is possible not only to improve the lightextraction efficiency by the light reflecting layer but also to improvethe luminance of the specific sub pixel 100 by causing that sub pixel100 to have a different luminance. In the case of increasing theluminance of sub pixel 100B using a reflector 112B with a higherinclined surface height relative to that of the other sub pixels 100R,100G and 100W, each of the sub pixels 100 can achieve the same (orsimilar) lifespan deterioration.

Further, in FIG. 8A, the example in which the inclined surface height ofthe reflector 112B is higher than that of the other reflectors and inwhich the inclined surface heights of the other reflectors (that is, thereflector 112G, the reflector 112R, and the reflector 112W) are equal,as indicated in Formula (2)′, has been described. However, the relationindicated in Formula (2)′ is an example, and the reflector 112 whoseinclined surface height is changed is arbitrary as long as the inclinedsurface height of the reflector 112 of the specific sub pixel 100 isdifferent from the inclined surface heights of the other sub pixels 100.For example, the relation of inclined surface heights indicated inFormula (2) could be used (thereby increasing the luminance of the subpixel 100W to increase the luminance of the pixel 10 as a whole).

Further, an example in which the inclined surface height of thereflector 112 of one sub pixel 100 as the specific sub pixel 100 ischanged has been described, but the number of specific sub pixels 100may be two or more. For example, the inclined surface heights of boththe reflectors 112W and 112B of the sub pixels 100W and 100B may be madeequal to each other and higher than the inclined surface heights of thereflectors 112R and 112G of the sub pixels 100R and 100G. It will alsobe appreciated that, more generally, each reflector 112 (or, at least,each of a portion of the reflectors 112) may have a different respectiveinclined surface height.

As illustrated in FIG. 8B, in a pixel 10 of a second variant of thefourth embodiment, only a portion of the upper portion 111B is separatedfrom the lower portion 111A by the gap 800 whilst the remaining portionof the upper portion 111B is not separated from (that is, is connectedto) the lower portion 111A. In particular, a portion 801 of the upperportion 111B comprising the reflector of one of the sub pixels(reflector 112B of sub pixel 100B, in this example) is not separatedfrom the lower portion 111A (that is, the portion 801 is connected tothe lower portion 111A) whereas another portion 802 of the upper portion111B comprising at least part of each of the reflectors of the other subpixels (reflectors 112R, 112G and 112W of sub pixels 100R, 100G and100W, in this example) is separated from the lower portion 111A (thatis, the portion 802 is not connected to the lower portion 111A). In theexample of FIG. 8B, the reflector 112B of the portion 801 of the upperportion 111B extends through part of the color filter 131B of the subpixel 100B and part of the neighboring color filters 131R and 131G ofthe sub pixels 100R and 100G in order to connect with the lower portion111A.

Due to there being a gap 800 between the portion 802 of the upperportion 111B and the lower portion 111A but no gap 800 between theportion 801 of the upper portion 111B and the lower portion 111A (for agiven reflector height as measured from a top surface 803 of the colorfilters 131), the surface area of the inclined surface of the reflectorcomprised by the portion 801 (reflector 112B of sub pixel 100B, in thisexample) is greater than the surface area of the inclined surface of thereflectors of which at least a part is comprised by the portion 802(reflectors 112R, 112G and 112W of sub pixels 100R, 100G and 100W, inthis example).

In the pixel 10 of FIG. 8B, the luminance of a specific sub pixel 100 isincreased because of the differing inclined surface area of thereflector 112 of the specific sub pixel 100 among the four sub pixels100. For example, when the inclined surface area of the reflector 112Bof the sub pixel 100B is higher that of the other sub pixels (as shownin FIG. 8B), a region in which light from the organic light emittingelement 101B undergoes total reflection increases, and thus theluminance of the sub pixel 100B relative to that of the other sub pixelsis improved. Further, in the pixel 10 of FIG. 8B, since the inclinedsurface area of the reflector 112 is changed without changing the lightemitting area or the pitch arrangement of each sub pixel 100, it ispossible to easily achieve high definition.

As described above, in the pixel 10 of FIG. 8B, the inclined surfacearea of the reflector 112 with respect to the organic light emittingelement 101 serving as the light emitting portion is determined for eachsub pixel 100 so that only the inclined surface area of the reflector112 of the specific sub pixel 100 is different from the inclined surfaceareas of the reflectors 112 of the other sub pixels 100. Accordingly, inthe pixel 10 of FIG. 8B, it is possible not only to improve the lightextraction efficiency by the light reflecting layer but also to improvethe luminance of the specific sub pixel 100 by causing that sub pixel100 to have a different luminance. In the case of increasing theluminance of sub pixel 100B using a reflector 112B with a higherinclined surface area relative to that of the other sub pixels 100R,100G and 100W, each of the sub pixels 100 can achieve the same (orsimilar) lifespan deterioration.

Further, in FIG. 8B, the example in which the inclined surface area ofthe reflector 112B is higher than that of the other reflectors and inwhich the inclined surface areas of the other reflectors (that is, thereflector 112G, the reflector 112R, and the reflector 112W) are equalhas been described. However, this is only an example, and the reflector112 whose inclined surface area is changed (by determining whichportion(s) of the upper portion 111B are connected to the lower portion111A and which are not) is arbitrary as long as the inclined surfacearea of the reflector 112 of the specific sub pixel 100 is differentfrom the inclined surface areas of the other sub pixels 100. Forexample, the reflector 112W of the sub pixel 100W may have the largestinclined surface area and the other sub pixels may have smaller, equalinclined surface areas (thereby increasing the luminance of the subpixel 100W and increasing the luminance of the pixel 10 as a whole).

Further, an example in which the inclined surface area of the reflector112 of one sub pixel 100 as the specific sub pixel 100 is changed hasbeen described, but the number of specific sub pixels 100 may be two ormore, for example, the inclined surface areas of both the reflectors112W and 112B of the sub pixels 100W and 100B may be made equal to eachother and higher than the inclined surface areas of the reflectors 112Rand 112G of the sub pixels 100R and 100G. It will also be appreciatedthat, more generally, each reflector 112 (or, at least, each of aportion of the reflectors 112) may have a different respective inclinedsurface area (e.g. by adjusting the size of the gap between eachreflector 112 and the lower portion 111A).

(Fifth Example of Structure of Pixel)

FIGS. 9A, 9B and 9C each show a main part cross-sectional viewillustrating a part of a structure of a pixel according to variants of afifth embodiment. A structure of a pixel 10 according to the fifthembodiment will be described below with reference to these main partcross-sectional views.

In the above-mentioned embodiments, each organic light emitting element101 employs a structure that emits white light which (where necessary)then travels through a color filter (e.g. for sub pixels 100R, 100B and100G). Alternatively, each organic light emitting element 101 may emit aspecific color of light (rather than white light). Thus, for example,there may be a red light emitting element 101R emitting red light, ablue light emitting element 101B emitting blue light and a green lightemitting element 101G emitting green light. In this case, no colorfilters are required because the light emitted from each light emittingelement 101 is already the desired color.

The pixels 10 of the fifth embodiment use such colored light emittingelements 101. These colored light emitting elements are structurallysimilar to the white light emitting elements of the above-mentionedembodiments, except that the organic layer of each light emittingelement includes a light emitting layer made of an organic lightemitting material which emits colored (rather than white) light. Inparticular, the relative positions of the anode, cathode and organiclayer of each light emitting element (not shown) are the same aspreviously described for the white light emitting elements of theabove-mentioned embodiments.

In the embodiments of FIGS. 9A, 9B and 9C, each light emitting element101 is a colored light emitting element and there is no white lightemitting element. Furthermore, each pixel 10 may comprise a plurality oflight emitting elements of a certain color (in this case, each pixel 10comprises two red light emitting elements 101R).

As illustrated in FIG. 9A, in a pixel 10 of a first variant of the fifthembodiment, the first member 111 comprises a reflector 112R, 112B and112G of each sub pixel 100R, 100B and 100G. The inclined surface heightof the reflector of one of the sub pixels (reflector 112B of sub pixel100B, in this example) is higher than the inclined surface heights ofthe reflectors of the other sub pixels (reflectors 112R and 112G of subpixels 100R and 100G, in this example). The inclined surface heights ofthe reflectors of the other sub pixels are equal to each other.

In the pixel 10 of FIG. 9A, the luminance of a specific sub pixel 100 isincreased by differing the inclined surface height of the reflector 112of the specific sub pixel 100 among the four sub pixels 100. Forexample, when the inclined surface height of the reflector 112B of thesub pixel 100B is higher than that of the other sub pixels (as shown inFIG. 9A), a region in which light from the organic light emittingelement 101B undergoes total reflection increases, and thus theluminance of the sub pixel 100B relative to that of the other sub pixelsis improved. Further, in the pixel 10 of FIG. 9A, since the inclinedsurface height of the reflector 112 is changed without changing thelight emitting area or the pitch arrangement of each sub pixel 100, itis possible to easily achieve high definition.

As described above, in the pixel 10 of FIG. 9A, the inclined surfaceheight of the reflector 112 with respect to the organic light emittingelement 101 serving as the light emitting portion is determined for eachsub pixel 100 so that only the inclined surface height of the reflector112 of the specific sub pixel 100 is different from the inclined surfaceheights of the reflectors 112 of the other sub pixels 100. Accordingly,in the pixel 10 of FIG. 9A, it is possible not only to improve the lightextraction efficiency by the light reflecting layer but also to improvethe luminance of the specific sub pixel 100 by causing that sub pixel100 to have a different luminance. In the case of increasing theluminance of sub pixel 100B using a reflector 112B with a higherinclined surface height relative to that of the other sub pixels 100Rand 100G, each of the sub pixels 100 can achieve the same (or similar)lifespan deterioration.

Further, in FIG. 9A, the example in which the inclined surface height ofthe reflector 112B is higher than that of the other reflectors and inwhich the inclined surface height of the other reflectors (that is, thereflector 112G and the reflector 112R) are equal has been described.However, this is only an example, and the reflector 112 whose inclinedsurface height is changed is arbitrary as long as the inclined surfaceheight of the reflector 112 of the specific sub pixel 100 is differentfrom the inclined surface heights of the other sub pixels 100.

Further, an example in which the inclined surface height of thereflector 112 of one sub pixel 100 as the specific sub pixel 100 ischanged has been described, but the number of specific sub pixels 100may be two or more, for example, the inclined surface heights of boththe reflectors 112G and 112B of the sub pixels 100G and 100B may be madeequal to each other and higher than the inclined surface heights of thereflectors 112R of the sub pixels 100R. It will also be appreciatedthat, more generally, each reflector 112 (or, at least, each of aportion of the reflectors 112) may have a different respective inclinedsurface height.

As illustrated in FIG. 9B, in a pixel 10 of a second variant of thefifth embodiment, the first member 111 comprises a reflector for onlyone of the sub pixels (reflector 112B of sub pixel 100B, in thisexample).

In the pixel 10 of FIG. 9B, the luminance of a specific sub pixel 100 isincreased by providing a reflector 112 only for that specific sub pixel100 among the four sub pixels 100. For example, when a reflector 112Bfor sub pixel 100B is provided, a region in which light from the organiclight emitting element 101B undergoes total reflection increases, andthus the luminance of the sub pixel 100B relative to that of the othersub pixels is improved. Further, in the pixel 10 of FIG. 9B, since thereflector 112 of the specific sub pixel is provided without changing thelight emitting area or the pitch arrangement of each sub pixel 100, itis possible to easily achieve high definition.

In the pixel 10 of FIG. 9B, it is possible not only to improve the lightextraction efficiency by the light reflecting layer but also to improvethe luminance of the specific sub pixel 100 by causing that sub pixel100 to have a different luminance. In the case of increasing theluminance of sub pixel 100B using a reflector 112B (without using areflector for the other sub pixels 100R and 100G), each of the subpixels 100 can achieve the same (or similar) lifespan deterioration.

In the pixel 10 of FIG. 9B, an example in which a reflector 112B isprovided only for sub pixel 100B has been described. However, this isonly an example, and the sub pixel 100 to which a reflector 112 isprovided may be a different sub pixel.

In the pixel 10 of FIG. 9B, an example in which a reflector 112 isprovided only to one specific sub pixel 100 has been described. However,the number of specific sub pixels 100 may be two or more. That is, moregenerally, a reflector 112 may be provided to a portion of the subpixels 100 of a pixel 10 whereas a remaining portion of the sub pixels100 of the pixel 10 are not provided with a reflector 112. This improvesthe luminance of the specific sub pixels 100 to which a reflector 112 isprovided.

As illustrated in FIG. 9C, in a pixel 10 of a third variant of the fifthembodiment, the first member 111 comprises a first (lower) portion 111Aand a second (upper) portion 111B. The lower portion 111A comprises thelight emitting elements 101R, 101B and 101G of each sub pixel 100R, 100Band 100G and the upper portion 111B comprises a reflector 112R, 112B and112G of each sub pixel 100R, 100B and 100G.

The lower and upper portions 111A and 111B are separated by a gap whichvaries in size for different respective facing portions of the lower andupper portions 111A and 111B. In the example of FIG. 9C, the size of thegap 903 between a portion 901 of the upper portion 111B comprising thereflector of one of the sub pixels (reflector 112B of sub pixel 100B, inthis example) and the lower portion 111A is smaller than the size of thegap 904 between another portion 902 of the upper portion 111B comprisingat least part of each of the reflectors of the other sub pixels(reflectors 112R and 112G of sub pixels 100R and 100G, in this example)and the lower portion 111A. In the example of FIG. 9C, the surface 905of the lower portion 111A facing the upper portion 111B comprises aplanarized layer 907 into which the portions 901 and 902 of the upperportion 111B are embedded at different positions with respect to thelower portion 111A so as to provide the gaps of different sizes betweenthe portions 901 and 902 of the upper portion 111B and the lower portion111A. The planarized layer 907 is formed of a transmissive materialthrough which light emitted by each of the light emitting elements 101R,101B and 101G can pass. The planarized layer 907 may be formed of, forexample, a resin such as an acrylic resin, a polyimide resin, a siliconresin or the like.

Due to there being a gap of a greater size between the portion 902 ofthe upper portion 111B and the lower portion 111A and a gap of a smallersize between the portion 901 of the upper portion 111B and the lowerportion 111A (for a given reflector height as measured from a topsurface 906 of the planarized layer 907), the surface area of theinclined surface of the reflector comprised by the portion 901(reflector 112B of sub pixel 100B, in this example) is greater than thesurface area of the inclined surface of the reflectors of which at leasta part is comprised by the portion 902 (reflectors 112R and 112G of subpixels 100R and 100G).

In the pixel 10 of FIG. 9C, the luminance of a specific sub pixel 100 isincreased because of the differing inclined surface area of thereflector 112 of the specific sub pixel 100 among the four sub pixels100. For example, when the inclined surface area of the reflector 112Bof the sub pixel 100B is higher that of the other sub pixels (as shownin FIG. 9C), a region in which light from the organic light emittingelement 101B undergoes total reflection increases, and thus theluminance of the sub pixel 100B relative to that of the other sub pixelsis improved. Further, in the pixel 10 of FIG. 9C, since the inclinedsurface area of the reflector 112 is changed without changing the lightemitting area or the pitch arrangement of each sub pixel 100, it ispossible to easily achieve high definition.

As described above, in the pixel 10 of FIG. 9C, the inclined surfacearea of the reflector 112 with respect to the organic light emittingelement 101 serving as the light emitting portion is determined for eachsub pixel 100 so that only the inclined surface area of the reflector112 of the specific sub pixel 100 is different from the inclined surfaceareas of the reflectors 112 of the other sub pixels 100. Accordingly, inthe pixel 10 of FIG. 9C, it is possible not only to improve the lightextraction efficiency by the light reflecting layer but also to improvethe luminance of the specific sub pixel 100 by causing that sub pixel100 to have a different luminance. In the case of increasing theluminance of sub pixel 100B using a reflector 112B with a higherinclined surface area relative to that of the other sub pixels 100R and100G, each of the sub pixels 100 can achieve the same (or similar)lifespan deterioration.

Further, in FIG. 9C, the example in which the inclined surface area ofthe reflector 112B is higher than that of the other reflectors and inwhich the inclined surface areas of the other reflectors (that is, thereflector 112G and the reflector 112R) are equal has been described.However, this is only an example, and the reflector 112 whose inclinedsurface area is changed (by determining the size of the gap between theportion of the upper portion 111B comprising that reflector 112 and thelower portion 111A) is arbitrary as long as the inclined surface area ofthe reflector 112 of the specific sub pixel 100 is different from theinclined surface areas of the other sub pixels 100.

Further, an example in which the inclined surface area of the reflector112 of one sub pixel 100 as the specific sub pixel 100 is changed hasbeen described, but the number of specific sub pixels 100 may be two ormore. That is, more generally, the size of the gap between the upperportion 111B and lower portion 111A of the first member 111 may bevaried such that the inclined surface area of the reflector of a portionof the sub pixels 100 of a pixel 10 is greater than that of thereflector of a remaining portion of the sub pixels 100 of the pixel 10.This improves the luminance of the specific sub pixels 100 to which areflector 112 with a greater inclined surface area is provided. It willalso be appreciated that, more generally, each reflector 112 (or, atleast, each of a portion of the reflectors 112) may have a differentrespective inclined surface area (e.g. by adjusting the size of the gapbetween each reflector 112 and the lower portion 111A).

(Sixth Example of Structure of Pixel)

FIGS. 10A and 10B each show a main part cross-sectional viewillustrating a part of a structure of a pixel according to variants of asixth embodiment. A structure of a pixel 10 according to the sixthembodiment will be described below with reference to these main partcross-sectional views.

In the above-mentioned embodiments, the light emitting element 101 ofeach sub pixel 100 comprises an organic layer with a structuresandwiched between an anode electrode and a cathode electrode (thecathode being above the anode in the FIGS). The cathode (formed of ITO,for example) is transparent so that light emitted by the organic layeris transmitted through the cathode to the reflector 112 of that subpixel 100. On the other hand, the anode (formed of Al, Cu or the like,for example) is reflective so that light emitted by the organic layer isreflected by the anode rather than being transmitted through it. Such anarrangement is known as a top emission OLED display type. The presenttechnology is not limited to such an arrangement, however. In analternative embodiment, it is the anode which is transparent and thecathode which is reflective so that light emitted by the organic layerof each sub pixel 100 is transmitted through the anode to the reflector112 of that sub pixel 100 but is reflected by the cathode rather thanbeing transmitted through it. In this case, the anode is formed of ITO,for example, and the cathode is formed of Al, Cu or the like, forexample. Such an arrangement is known as a bottom emission OLED type.The variants of the sixth embodiment shown in FIGS. 10A and 10Brepresent example bottom emission OLED type pixels.

As illustrated in FIG. 10A, in a pixel 10 of a first variant of thesixth embodiment, the first member 111 comprises a first (lower) portion111A and a second (upper) portion 111B. The upper portion 111B comprisesthe light emitting elements 101R, 101B and 101G of each sub pixel 100R,100B and 100G and the lower portion 111A comprises a reflector 112R,112B and 112G of each sub pixel 100R, 100B and 100G.

The lower and upper portions 111A and 111B are separated by a gap whichvaries in size for different respective facing portions of the lower andupper portions 111A and 111B. In the example of FIG. 10A, the size ofthe gap 1004 between a portion 1001 of the lower portion 111A comprisingthe reflector of one of the sub pixels (reflector 112B of sub pixel100B, in this example) and the upper portion 111B is smaller than thesize of the gap 1005 between another portion 1002 of the lower portion111A comprising at least part of each of the reflectors of the other subpixels (reflectors 112R and 112G of sub pixels 100R and 100G in thisexample) and the upper portion 111B. In the example of FIG. 10A, thesurface 1006 of the upper portion 111B facing the lower portion 111Acomprises a planarized layer 1000 into which the portions 1001 and 1002of the lower portion 111A are embedded at different positions withrespect to the upper portion 111B so as to provide the gaps of differentsizes between the portions 1001 and 1002 of the lower portion 111A andthe upper portion 111B. The planarized layer 1000 is formed of atransmissive material through which light emitted by each of the lightemitting elements 101R, 101B and 101G can pass. The planarized layer1000 may be formed of, for example, a resin such as an acrylic resin, apolyimide resin, a silicon resin or the like.

Due to there being a gap 1005 of a greater size between the portion 1002of the lower portion 111A and the upper portion 111B and a gap 1004 of asmaller size between the portion 1001 of the lower portion 111A and theupper portion 111B (and given that each reflector of the lower portion111A extends to a bottom surface 1007 of the planarized layer 1000), thesurface area of the inclined surface of the reflector comprised by theportion 1001 (reflector 112B of sub pixel 100B, in this example) isgreater than the surface area of the inclined surface of the reflectorsof which at least a part is comprised by the portion 1002 (reflectors112R and 112G of sub pixels 100R and 100G, this this example).

In the pixel 10 of FIG. 10A, the luminance of a specific sub pixel 100is increased because of the differing inclined surface area of thereflector 112 of the specific sub pixel 100 among the four sub pixels100. For example, when the inclined surface area of the reflector 112Bof the sub pixel 100B is higher than that of the other sub pixels (asshown in FIG. 10A), a region in which light from the organic lightemitting element 101B undergoes total reflection increases, and thus theluminance of the sub pixel 100B relative to that of the other sub pixelsis improved. Further, in the pixel 10 of FIG. 10A, since the inclinedsurface area of the reflector 112 is changed without changing the lightemitting area or the pitch arrangement of each sub pixel 100, it ispossible to easily achieve high definition.

As described above, in the pixel 10 of FIG. 10A, the inclined surfacearea of the reflector 112 with respect to the organic light emittingelement 101 serving as the light emitting portion is determined for eachsub pixel 100 so that only the inclined surface area of the reflector112 of the specific sub pixel 100 is different from the inclined surfaceareas of the reflectors 112 of the other sub pixels 100. Accordingly, inthe pixel 10 of FIG. 10A, it is possible not only to improve the lightextraction efficiency by the light reflecting layer but also to improvethe luminance of the specific sub pixel 100 by causing that sub pixel100 to have a different luminance. In the case of increasing theluminance of sub pixel 100B using a reflector 112B with a higherinclined surface area relative to that of the other sub pixels 100R and100G, each of the sub pixels 100 can achieve the same (or similar)lifespan deterioration.

Further, in FIG. 10A, the example in which the inclined surface area ofthe reflector 112B is higher than that of the other reflectors and inwhich the inclined surface areas of the other reflectors (that is, thereflector 112G and the reflector 112R) are equal has been described.However, this is only an example, and the reflector 112 whose inclinedsurface area is changed (by determining the size of the gap between theportion of the lower portion 111A comprising that reflector 112 and theupper portion 111A) is arbitrary as long as the inclined surface area ofthe reflector 112 of the specific sub pixel 100 is different from theinclined surface areas of the other sub pixels 100.

Further, an example in which the inclined surface area of the reflector112 of one sub pixel 100 as the specific sub pixel 100 is changed hasbeen described, but the number of specific sub pixels 100 may be two ormore. That is, more generally, the size of the gap between the upperportion 111B and lower portion 111A of the first member 111 may bevaried such that the inclined surface area of the reflector of a portionof the sub pixels 100 of a pixel 10 is greater than that of thereflector of a remaining portion of the sub pixels 100 of the pixel 10.This improves the luminance of the specific sub pixels 100 to which areflector 112 with a greater inclined surface area is provided. It willalso be appreciated that, more generally, each reflector 112 (or, atleast, each of a portion of the reflectors 112) may have a differentrespective inclined surface area (e.g. by adjusting the size of the gapbetween each reflector 112 and the upper portion 111B). Alternatively,each reflector may have the same inclined surface area (e.g. by ensuringthat the size of the gap between each of the reflectors 112 and theupper portion 111B is the same), thereby providing an equally improvedluminance of each of the sub pixels 100 and thus an improved overallluminance of the pixel 10.

FIG. 10B shows a pixel 10 of a second variant of the sixth embodiment.The pixel 10 of FIG. 10B is the same as that of FIG. 10A, except thatthe lower and upper portions 111A and 111B of the first member 111 areseparated by a gap 1003 of a constant size and that the reflector of oneof the sub pixels (reflector 112B of sub pixel 100B, in this example)extends in a direction towards the bottom surface 1007 of the planarizedlayer 1000 to a greater extent than the extent to which the reflectorsof the other sub pixels (reflectors 112R and 112G of sub pixels 100R and100G, in this example) extend towards the bottom surface 1007 of theplanarized layer 1000. The extent to which a reflector 112 extendstowards the bottom surface 1007 of the planarized layer 1000 may bereferred to as the reflector depth. A reflector 112 (e.g. reflector112B) which extends towards the bottom surface 1007 of the planarisedlayer 1000 to a greater extent (so that the distance between a lower end1008 of the reflector 112 and the bottom surface 1007 of the planarisedlayer 1000 is smaller) is said to have a greater depth. A reflector 112(e.g. reflectors 112R and 112G) which extends towards the bottom surface1007 of the planarised layer 1000 to a lesser extent (so that thedistance between a lower end 1008 of the reflector 112 and the bottomsurface 1007 of the planarised layer 1000 is smaller) is said to have alesser depth. In the example of FIG. 10B, the reflector depths of thereflectors other than the reflector 112B with the deepest reflectordepth are equal to each other.

In the pixel 10 of FIG. 10B, the luminance of a specific sub pixel 100is increased by differing the reflector depth of the reflector 112 ofthe specific sub pixel 100 among the four sub pixels 100. For example,when the reflector depth of the reflector 112B of the sub pixel 100B isgreater than that of the other sub pixels (as shown in FIG. 10B), aregion in which light from the organic light emitting element 101Bundergoes total reflection increases. This is because the greaterreflector depth provides a greater surface area of the reflector fromwhich light emitted by the light emitting element 101B is reflected. Theluminance of the sub pixel 100B relative to that of the other sub pixelsis therefore improved. Further, in the pixel 10 of FIG. 10B, since thereflector depth of the reflector 112 is changed without changing thelight emitting area or the pitch arrangement of each sub pixel 100, itis possible to easily achieve high definition.

As described above, in the pixel 10 of FIG. 10B, the reflector depth ofthe reflector 112 with respect to the organic light emitting element 101serving as the light emitting portion is determined for each sub pixel100 so that only the reflector depth of the reflector 112 of thespecific sub pixel 100 is different from the reflector depth of thereflectors 112 of the other sub pixels 100. Accordingly, in the pixel 10of FIG. 10B, it is possible not only to improve the light extractionefficiency by the light reflecting layer but also to improve theluminance of the specific sub pixel 100 by causing that sub pixel 100 tohave a different luminance. In the case of increasing the luminance ofsub pixel 100B using a reflector 112B with a reflector depth relative tothat of the other sub pixels 100R and 100G, each of the sub pixels 100can achieve the same (or similar) lifespan deterioration.

Further, in FIG. 10B, the example in which the reflector depth of thereflector 112B is greater than that of the other reflectors and in whichthe reflector depth of the other reflectors (that is, the reflector 112Gand the reflector 112R) are equal has been described. However, this isonly an example, and the reflector 112 whose reflector depth is changedis arbitrary as long as the reflector depth of the reflector 112 of thespecific sub pixel 100 is different from the reflector depths of theother sub pixels 100.

Further, an example in which the reflector depth of the reflector 112 ofone sub pixel 100 as the specific sub pixel 100 is changed has beendescribed, but the number of specific sub pixels 100 may be two or more.For example, the reflector depths of both the reflectors 112G and 112Bof the sub pixels 100G and 100B may be made equal to each other andgreater than the reflector depths of the reflectors 112R of the subpixels 100R. It will also be appreciated that, more generally, eachreflector 112 (or, at least, each of a portion of the reflectors 112)may have a different respective reflector depth. Alternatively, eachreflector may have the same reflector depth, thereby providing anequally improved luminance of each of the sub pixels 100 and thus animproved overall luminance of the pixel 10.

Although the pixels 10 of FIGS. 10A and 10B use colored light emittingelements 101R, 101B and 101G, it will be appreciated that,alternatively, white light emitting elements 101R, 101B and 101G couldbe used. In this case, the pixel 10 comprises a further layer attachedto the bottom surface 1007 of the planarized layer 1000 comprisingappropriate color filters (like those shown in FIGS. 5, 6, 7 and 8A and8B, for example). In such a layer, a red color filter (e.g. color filter101R) is aligned with the light emitting elements 101R, a blue colorfilter (e.g. color filter 131B) is aligned with the light emittingelement 101B and a green color filter (e.g. color filter 131G) isaligned with light emitting element 101G.

(Seventh Example of Structure of Pixel)

FIG. 11 shows a main part cross-sectional view illustrating a part of astructure of a bottom emission sub pixel 100 according to a seventhembodiment. In a pixel comprising a plurality of sub pixels 100according to the seventh embodiment, each sub pixel 100 comprises thestructure shown in FIG. 11 .

The sub pixel 100 comprises a substrate 1101 comprising the necessarypixel circuitry (not shown). The substrate 1101 is a thin filmtransistor (TFT) substrate, for example. A planarized layer 1102 isformed on the substrate 1101. The planarized layer 1102 is formed of,for example, a resin such as an acrylic resin, a polyimide resin, asilicon resin or the like. An anode 121 is formed over a first portionof the planarized layer 1102. An insulating layer 1103 is formed over asecond portion of the planarized layer 1102. The insulating layer 1103is formed of an insulating material. Like the planarized layer 1102, theinsulating layer 1103 may be formed of, for example, a resin such as anacrylic resin, a polyimide resin, a silicon resin or the like. Theplanarized layer 1102 and insulating layer 1103 may be made of the sameor different materials. A groove 1106 is formed over a third portion ofthe planarized layer 1102. The groove 1106 extends through theinsulating layer 1103 and into the planarized layer 1102. An organiclayer 1104 (comprising a light emitting layer) and a cathode layer 1105are formed as adjacent layers (forming a combined layer) over the anode121, insulating layer 1103 and the inside surface of the groove 1106.

In the bottom emission pixel of FIG. 11 , the anode 121 (formed of ITO,for example) is transparent. On the other hand, the cathode 1105 (formedof Al, Cu or the like, for example) is reflective. The formation of theorganic layer 1104 and cathode 1105 over the anode 121 (so that theorganic layer 1104 is sandwiched between the anode 121 and cathode 1105)causes a portion of the organic layer 1104 to be in contact with boththe anode 121 and the cathode 1105. Light is therefore emitted by thisportion of the organic layer 1104 which, together with the anode 121 andcorresponding portion of the cathode 1105, thus forms a light emittingelement.

Light rays 1107 emitted by this light emitting element travel throughthe anode 121 and planarized layer 1102 and are reflected at one or moreof the boundary between the planarized layer 1102 (with a firstrefractive index) and the organic layer 14 (with a second refractiveindex), the boundary between the organic layer 1104 and the cathode 1105(with a third refractive index), and the reflective cathode 1105.

In an embodiment, a pixel comprising sub pixels 100 of the type shown inFIG. 11 is manufactured by first forming the substrate 1101 (e.g. TFTsubstrate) using a suitable process (such processes are known in the artand are therefore not discussed in detail here). Then, the planarizedlayer 1102 is formed on the substrate 1101 using a planarizing process.Then, the anode 121 is formed on the planarized layer 1102. This is doneusing a CVD (chemical vapor deposition) film forming process, forexample.

The insulating layer 1103 is then formed on the planarized layer 1102and anode 121. This is carried out using a further planarizing process,for example. Portions of the insulating layer 1103 and/or planarizedlayer 1102 are then removed in order to expose the anode 121 and formthe groove 1106. This is carried out by, for example, repeatedly forminga photoresist layer on the insulating layer 1103 and/or planarized layer1102, exposing a portion of the photoresist layer to a predeterminedpattern of light, carrying out a developing process to remove theexposed portion of the photoresist layer and etching a portion of theinsulating layer 1103 and/or planarized layer 1102 exposed by theremoved portion of the photoresist layer. This process is repeated toetch away successive layers of the insulating layer 1103 and/orplanarized layer 1102 until the anode 121 is exposed and the groove 1106is formed.

The organic and cathode layers 1104 and 1105 are then deposited over theexposed anode 121, the remaining portions of the insulating layer 1103and the inside surface of the groove 1106 (again using a CVD filmforming process, for example). Alternatively, the organic layer 1104 maybe deposited on the anode 121 only (that is, not over the remainingportions of the insulating layer 1103 and the inside surface of thegroove 1106) whilst the cathode layer 1105 is deposited over the exposedanode 121, the remaining portions of the insulating layer 1103 and theinside surface of the groove 1106.

(Eighth Example of Structure of Pixel)

FIGS. 12A and 12B each show a main part cross-sectional viewillustrating a part of a structure of a bottom emission pixel accordingto variants of an eighth embodiment. A structure of a pixel 10 accordingto the eighth embodiment will be described below with reference to thesemain part cross-sectional views.

The pixels 10 of FIGS. 12A and 12B are each the same as that of FIG. 10Aexcept that, rather than having a first member comprising an upperportion 111B comprising the light emitting elements 101R, 101B and 101Gof each sub pixel 100R, 100B and 100G and a lower portion 111Acomprising a reflector 112R, 112B and 112G of each sub pixel 100R, 100Band 100G, there is a one piece first member 111 and the reflectors 112R,112B and 112G are the boundaries of notch portions 1200 at which lightemitted by each of the light emitting elements 101 is reflected byinternal reflection (e.g. total internal reflection). The notch portions1200 provide gaps (e.g. air or vacuum gaps) with a lower refractiveindex than that of the material (a resin such as an acrylic resin, apolyimide resin, a silicon resin or the like) within which the notchportions are formed, thereby providing the boundaries at which lightemitted by the light emitting elements is reflected.

The notch portions 1200 of FIGS. 12A and 12B are positioned with respectto the first member 111 similarly to the way in which the portions ofmaterial forming the lower portion 111A forming the reflectors 112 ofFIG. 10A are positioned with respect to the upper portion 111B. That is,an upper surface 1201 of each notch portion is separated from the firstmember 111 by a varying distance. In the example of FIG. 12A, thedistance between the respective upper surfaces 1201 of notch portions1200B and 1200C comprising the reflector of one of the sub pixels(reflector 112B of sub pixel 100B, in this example) and the first member111 is smaller than the distance between the respective upper surfaces1201 of the remaining notch portions 1200A, 1200D and 1200E comprisingat least part of each of the reflectors of the other sub pixels(reflectors 112R and 112G of sub pixels 100R and 100G in this example)and the first member 111.

In the example of FIG. 12A, the surface 1203 of the first member 111facing the notch portions comprises a planarized layer 1202 in which thenotch portions 1200 are formed. The planarized layer 1202 is formed of atransmissive material through which light emitted by each of the lightemitting elements 101R, 101B and 101G can pass. The planarized layer1202 may be formed of, for example, a resin such as an acrylic resin, apolyimide resin, a silicon resin or the like. In the example of FIG.12B, rather than the notch portions being formed in the planarized layer1202, a separate notched layer 1203 (formed of a further resin, forexample) is provided on the planarized layer 1203 and it is the separatenotched layer into which the notch portions 1200 are formed.

In the examples of FIGS. 12A and 12B, due to there being a greaterdistance between the notch portions 1200A, 1200D and 1200E and the firstmember 111 and a smaller distance between the notch portions 1200B and1200C and the first member 111 (and given that each notch portionextends to a bottom surface 1204 of the planarized layer 1202 or notchedlayer 1203), the surface area of the reflector 112B of sub pixel 100B isgreater than the surface area of reflectors 112R and 112G of sub pixels100R and 100G.

In the pixel 10 of FIGS. 12A and 12B, the luminance of a specific subpixel 100 is increased because of the differing surface area of thereflector 112 of the specific sub pixel 100 among the four sub pixels100. For example, when the surface area of the reflector 112B of the subpixel 100B is higher than that of the other sub pixels (as shown inFIGS. 12A and 12B), a region in which light from the organic lightemitting element 101B undergoes total reflection increases, and thus theluminance of the sub pixel 100B relative to that of the other sub pixelsis improved. Further, in the pixel 10 of FIGS. 12A and 12B, since theinclined surface area of the reflector 112 is changed without changingthe light emitting area or the pitch arrangement of each sub pixel 100,it is possible to easily achieve high definition.

As described above, in the pixel 10 of FIGS. 12A and 12B, the surfacearea of the reflector 112 with respect to the organic light emittingelement 101 serving as the light emitting portion is determined for eachsub pixel 100 so that only the surface area of the reflector 112 of thespecific sub pixel 100 is different from the inclined surface areas ofthe reflectors 112 of the other sub pixels 100. Accordingly, in thepixel 10 of FIGS. 12A and 12B, it is possible not only to improve thelight extraction efficiency by the light reflecting layer but also toimprove the luminance of the specific sub pixel 100 by causing that subpixel 100 to have a different luminance. In the case of increasing theluminance of sub pixel 100B using a reflector 112B with a higher surfacearea relative to that of the other sub pixels 100R and 100G, each of thesub pixels 100 can achieve the same (or similar) lifespan deterioration.

Further, in FIGS. 12A and 12B, the example in which the surface area ofthe reflector 112B is higher than that of the other reflectors and inwhich the surface areas of the other reflectors (that is, the reflector112G and the reflector 112R) are equal has been described. However, thisis only an example, and the reflector 112 whose surface area is changed(by determining the size of the gap between the notch portion whoseboundary defines that reflector 112 and the first member 111) isarbitrary as long as the surface area of the reflector 112 of thespecific sub pixel 100 is different from the inclined surface areas ofthe other sub pixels 100.

Further, an example in which the surface area of the reflector 112 ofone sub pixel 100 as the specific sub pixel 100 is changed has beendescribed, but the number of specific sub pixels 100 may be two or more.That is, more generally, the distance between the upper surface 1201 ofeach notch portion and the first member 111 may be varied such that thesurface area of the reflector of a portion of the sub pixels 100 of apixel 10 is greater than that of the reflector of a remaining portion ofthe sub pixels 100 of the pixel 10. This improves the luminance of thespecific sub pixels 100 to which a reflector 112 with a greater surfacearea is provided. It will also be appreciated that, more generally, eachreflector 112 (or, at least, each of a portion of the reflectors 112)may have a different respective inclined surface area (e.g. by adjustingthe distance between the upper surface 1201 of each notch portion andthe first member 111). Alternatively, each reflector may have the sameinclined surface area (e.g. by ensuring that the distance between theupper surface 1201 of each of the notch portions 1200 and the firstmember 111 is the same), thereby providing an equally improved luminanceof each of the sub pixels 100 and thus an improved overall luminance ofthe pixel 10.

It will furthermore be appreciated that the notch portions 1200 of FIGS.12A and 12B may a similar arrangement to that of FIG. 10A instead ofFIG. 10B. Namely, the distance between the upper surface 1201 of each ofthe notch portions 1200 and the first member 111 may be the same and aportion of the notch portions 1200 (e.g. the notch portions 1200B and1200C comprising the reflector 112B of sub pixel 100B) may extend in adirection towards the bottom surface 1204 of the planarized layer 1202or notched layer 1203 to a greater extent (providing a greater reflectordepth) than the extent to which a remaining portion of the notchportions 1200 (e.g. the remaining notch portions 1200A, 1200D and 1200E)extend towards the bottom surface 1204 of the planarized layer 1202 ornotched layer 1203 (providing a less reflector depth).

Although the pixels 10 of FIGS. 12A and 12B use colored light emittingelements 101R, 101B and 101G, it will be appreciated that,alternatively, white light emitting elements 101R, 101B and 101G couldbe used. In this case, the pixel 10 comprises a further layer attachedto the bottom surface 1204 of the planarized layer 1202 or notched layer1203 comprising appropriate color filters (like those shown in FIGS. 5,6, 7 and 8A and 8B, for example). In such a layer, a red color filter(e.g. color filter 101R) is aligned with the light emitting elements101R, a blue color filter (e.g. color filter 131B) is aligned with thelight emitting element 101B and a green color filter (e.g. color filter131G) is aligned with light emitting element 101G.

In the above-mentioned embodiments, each reflector 112 comprises a lightreflecting surface (e.g. a reflective surface of first member 111 or aboundary between a material with a higher refractive index and amaterial with a lower refractive index) with an area which may bedifferent for one or more of the sub pixels 100 of each pixel 10 inorder to change amount of reflected light for those sub pixels 100 andthus the output luminance of those sub pixels 100.

In the above-mentioned embodiments, the light reflecting surface of eachsub pixel 100 is an inclined surface and the area of the inclinedsurface of each sub pixel 100 is determined according to a length alongwhich that inclined surface extends in a stacking direction (with thegreater the length of the inclined surface, the greater the area overwhich light is reflected and the greater the amount of light which isreflected).

In some embodiments (e.g. those of FIGS. 5, 6, 8A, 9A, 9B and 10B), theinclined surfaces of all reflectors 112 extend from a common plane andthe length along which each inclined surface extends is determined bythe height or depth of that inclined surface. In the examples of FIGS.5, 6, 8A, 9A and 9B, the common plane is the plane along which each ofthe light emitting elements 101 is defined. In the example of FIG. 10B,the common plane is the top surface of the lower portion 111A of thefirst member 111 (which is parallel to the plane along which the lightemitting elements 101 are defined and separated from the plane alongwhich the light emitting elements 101 are defined by the gap 1003).

In other embodiments (e.g. those of FIGS. 7, 8B, 9C, 10A, 12A and 12B),at least one inclined surface extends from a plane at a differentposition in the stacking direction to the plane(s) at which each of theother inclined surface(s) extends. Each inclined surface may, however,extend such that all inclined surfaces meet in a common plane. In theexamples of FIGS. 7, 8B, 9C, 10A, 12A and 12B, the inclined surface ofreflector 112B extends from a different plane to that of the inclinedsurfaces of the other reflectors. However, all the inclined surfacesextend to meet in a common plane. In FIG. 7 , the common plane is thatdefined by the top of the first member 111 (on which the color filters131 are arranged). In FIGS. 8B and 9C, the common plane is that definedby the top of the upper portion 111B of the first member 111. In FIG.10A, the common plane is that defined by the bottom of the lower portion111A of the first member 111. In FIGS. 12A and 12B, the common plane isthat defined by the bottom of the planarized layers 1202 and 1203,respectively. The length along which each inclined surface extends istherefore varied by the position of the plane from which that inclinedsurface extends to the common plane.

In all of the above-mentioned embodiments, the length along which aninclined surface of each sub pixel 100 extends in the stacking direction(thereby defining the area of the inclined surface which reflects light)may be referred to as the height or depth of that inclined surfacerelative to the light emitting portion of that sub pixel 100. It will beappreciated that “height” and “depth” are relative terms in thatsomething measured as a “height” may equally be measured as a “depth” ifthe length concerned is considered from a different perspective (e.g. ifFIG. 5 is viewed upside down, then the “height” of each reflector 112becomes a “depth” and if FIG. 10A or 10B is viewed upside down, then the“depth” of each reflector 112 becomes a “height”). The terms “height”and “depth” should therefore be considered functionally equivalent andthe terms “height” or “depth” may be used interchangeably with theexpression “length which extends in a stacking direction”. The lengthalong which each reflector 112 extends in the stacking direction mayalso be referred to, more generally, as the distance between a firstplane which is coplanar with a first end of the reflector 112 (e.g. thetop of the reflector in the stacking direction) and a second plane whichis coplanar with a second end of the reflector 112 (e.g. the bottom ofthe reflector in the stacking direction).

In embodiments, the term “stacking direction” should be understood tomean the direction in which the display element 1 comprising the pixels10 and sub pixels 100 is formed by successively stacking one layer ontop of another. The layers include, for example, the first member 111(including, where present, the lower portion 111A and upper portion 111Bof the first member 111), the anode, organic layer and cathode of eachlight emitting element 101 and, where present, one or more planarizedlayers (such as planarized layers 907, 1000, 1106, 1202 and 1203).

It will be appreciated that the present technique may be applied moregenerally such that a plurality of pixels (each of which may comprise aplurality of sub pixels or may itself be a sub pixel) arranged in atwo-dimensional form include a first pixel, a second pixel and a thirdpixel. A first light reflecting portion (reflector 112) is locatedbetween the first pixel and the second pixel (so as to reflect lightemitted by either the first or second pixel) and a second lightreflecting portion (reflector 112) is located between the second pixeland the third pixel (so as to reflect light emitted by either the secondor third pixel). The height of the first and second light reflectingportions may be the same (in order to improve the perceived luminance ofeach pixel from which light is reflected equally). Alternatively, theheight of the first and second light reflecting portions may bedifferent (in order to improve the perceived luminance of one pixel fromwhich light is reflected over another).

In the above-mentioned embodiments, it will be appreciated that eachreflector 112 is an inclined reflective surface and that each pixel(which may comprise a plurality of sub pixels or may itself be a subpixel) emits light which is reflected by one or more of these surfaces.For example, in each of FIGS. 5, 6, 7, 8A, 8B, 9A, 9C, 10A, 10B, 12A and12B, each of the sub pixels 100 emits light which is reflected by twoinclined surfaces (that is, each sub pixel is said to have two inclinedsurfaces). In FIG. 9B, the blue sub pixel 100B emits light which isreflected by two inclined surfaces (that is, the blue sub pixel 100B hastwo inclined surfaces), each of one of the red sub pixels 100R and thegreen sub pixel 100G emits light which is reflected by one inclinedsurface (that is, each of these sub pixels has one inclined surface) andthe remaining red sub pixel 100R emits light which is not reflected byan inclined surface (that is, this sub pixel has no inclined surface).It will be appreciated that, in the above-mentioned embodiments, adifferent perceived luminance of a first pixel relative to a secondpixel is achieved by changing the height of at least one inclinedreflective surface of the first pixel with respect to the height of atleast one inclined reflective surface of the second pixel so as tochange the overall area over which light emitted by the first pixel isreflected with respect to the overall area over which light emitted bythe second pixel is reflected.

(Details of Structure of Reflector)

Next, a structure of the reflector 112 will be described in detail withreference to FIGS. 13 to 17 .

FIG. 13 is a conceptual diagram for describing reflection of light bythe reflector 112.

As illustrated in FIG. 13 , in the sub pixel 100, the light from (theanode electrode 121 of) the organic light emitting element 101 to thereflector 112 is omnidirectional, but the reflector 112 reflects lightincident at a predetermined total reflection angle or more but transmitslight incident at less than the angle.

For example, in FIG. 13 , the light beams L2 and L3 among light beams L1to L4 from the anode electrode 121 of the organic light emitting element101 are totally reflected by the reflector 112, while the light beam L4passes through the reflector 112.

Here, FIG. 14 illustrates a relation between a distance L (unit: nm) tothe inclined surface of the reflector 112 and an inclined surface heightH (unit: nm) of the reflector 112 at which the total reflection isperformed.

For example, in a case in which a width of the opening portion (theportion in which the anode electrode 121 is exposed) between thereflectors 112 is 2,000 nm, the distance L to the inclined surface ofthe reflector 112 is a maximum of 2,000 nm. In this case, the height Hsatisfying the total reflection condition is approximately 1,600 nm fromthe relation between L and H illustrated in FIG. 14 .

In other words, in the reflector 112, a reflection region has the heightH=1600 nm or more, and since the total reflection region increases asthe height (inclined surface height) H is increased, the luminance ofthe sub pixel 100 can be improved. In other words, it can be said thatthe luminance is improved by the increase in the reflection area withthe increase in the inclined surface height H.

Here, the height (inclined surface height) H satisfying the totalreflection condition can be obtained by, for example, the followingcalculation.

In other words, as illustrated in FIG. 15 , in a case in which anincidence angle (reflection angle) of light incident on the reflector112 is indicated by θ, α can be calculated by the following Formula (3).

α=tan⁻¹(H/(L+t))  (3)

Here, if the reflector angle (inclination angle) is indicated by β, arelation of the following Formula (4) is obtained by the exterior angletheorem of a triangle.

(90−θ)+α=β  (4)

Therefore, a relation of the following Formula (5) can be derived fromFormulas (3) and (4).

θ=90+α−β=90+tan⁻¹(H/(L+t))−β

tan⁻¹(H/(L+t))=θ+β−90

tan(θ+β−90)=H/(L+t)  (5)

Further, since t=H/tan β is obtained from the relation of tan β=H/t, arelation of the following Formula (6) can be derived on the basis ofFormula (5).

H=(L+t)×tan(θ+β−90)=(L+(H/tan β)×tan(θ+β−90)  (6)

Then, since the total reflection is performed at θ>θ_(max) (a criticalangle), the height H satisfying the relation of the following Formula(7) can be obtained.

H≥L×tan(θ_(max)+β−90)/(1−(tan(θ_(max)+β−90)/tan β))  (7)

Accordingly, the height (inclined surface height) H satisfying the totalreflection condition is obtained.

Here, a case in which a refractive index nA of the reflector 112 (forexample, SiO), that is, the refractive index nA of the surface of thefirst member 111 is 1.4, and a refractive index nB of an organic ELmaterial of the organic layer (for example, a layer 141 of FIG. 22 to bedescribed later) at an interface with the reflector 112 is 1.8 asillustrated in FIG. 15 is assumed. In this case, θ_(max) (criticalangle) at which the total reflection is performed has a relation of thefollowing Formula (8).

sin θ_(max)=sin θ_(max)/sin 90°=nA/nB  (8)

Then, a calculation result of the following Formula (9) is obtained bycalculating Formula (8).

θ_(max)=sin⁻¹(nA/nB)=sin⁻¹(1.4/1.8)=sin⁻¹(0.882)=51.3°  (9)

Since θ_(max)=51.3° is obtained as described above, if it is assumedthat L is 1000 nm, and β is 71°, H=808 nm can be obtained by solving thefollowing Formula (10) on the basis of Formula (7).

H=L×tan(θ_(max)+β−90)/(1−(tan(θ_(max)+β−90)/tanβ))=1000×tan(51.3°+71°−90°)/(1−(tan(51.3°+71°−90°/tan 71°))=808.07

Further, the inventors of the present technology analyzed the optimumreflector angle β and the width of the opening portion between thereflectors 112 (the size of the opening portion) by obtaining a changein the height (inclined surface height) H satisfying the totalreflection condition in a case in which the reflector angle β is changedby a detailed simulation. The result of the simulation is illustrated inFIG. 16 .

A table of FIG. 16 illustrates a value (unit: nm) of the height(inclined surface height) satisfying the total reflection condition(unit: degree) when the value (unit: degree) of reflector angle β andthe value (unit: nm) of the distance L to the inclined surface of thereflector 112 are changed.

Here, the table of FIG. 16 illustrates the values of the height Hobtained by calculating Formula (7) when β=60°, 65°, 68°, 70°, 71°, 73°,74°, 75°, and 80°, and L=10 nm, 100 nm, 500 nm, 1000 nm, 1500 nm, 2000nm, 2500 nm, and 3000 nm.

Further, it was found from the results of this simulation that it isdesirable that the width of the portion in which the organic lightemitting element 101 serving as the light emitting portion emits (theportion in which the anode electrode 121 is exposed), that is, the sizeof the opening portion be 3000 nm or less, and in that case, it isdesirable that the reflector angle β is 60° to 80°. An example of astructure satisfying such a total reflection condition is illustrated inFIG. 17 . In FIG. 17 , when β=71° and L=2000 nm, H=1616 nm.

(First Example of Manufacturing Process)

Next, a flow of a first example of a top emission pixel manufacturingprocess according to an embodiment of the present technology will bedescribed with reference to FIGS. 18 to 22 .

Further, in the first example of the manufacturing process, for the sakeof convenience of description, a flow of a process of manufacturing thesub pixels 100R and 100G as arbitrary sub pixels 100 constituting thepixel 10 will be described.

Here, first, a dry processing process is performed as illustrated in Aof FIG. 18 . With the dry processing process, anode electrodes 121R and121G are formed on a first member 111A. Further, for example, SiO₂ orthe like can be used as a material of the first member 111A. Further, areflective material such as Al, Cu or the like can be used as thematerial of the anode electrode 121.

Next, a CVD film forming process is performed as illustrated in B ofFIG. 18 . With the CVD film forming process, a first member 111B isformed on the anode electrodes 121R and 121G formed on the first member111A. Further, for example, P—SiO or the like can be used as a materialof the first member 111B.

Next, a resist coating process is performed as illustrated in C of FIG.18 . With the resist coating process, the first member 111B is coatedwith a photoresist 211.

Then, an exposure process is performed as illustrated in D of FIG. 19 .With the exposure process, a surface of the photoresist 211 is exposedto light in a pattern form using a photomask 221, so that a patternincluding the exposed portion (an exposed portion 212) and an unexposedportion (a portion excluding the exposed portion 212) is formed.

Then, a developing process is performed as illustrated in E of FIG. 19 .With the developing process, the exposed portion 212 of the photoresist211 is removed.

Then, an etching process is performed as illustrated in F of FIG. 19 .With the etching process, the portion excluding the portion masked bythe photoresist 211 is etched, and a part of the first member 111B isprocessed.

Then, a resist coating process is performed as illustrated in G of FIG.20 . With the resist applying process, the processed portion of thefirst member 111B is coated with the photoresist 211.

Next, an exposure process is performed as illustrated in H of FIG. 20 .With the exposure process, a surface of the photoresist 211 is exposedto light in a pattern form using a photomask 231, so that a patternincluding the exposed portions (exposed portions 213 and 214) and anunexposed portion (a portion excluding the exposed portions 213 and 214)is formed.

Then, a developing process is performed as illustrated in I of FIG. 20 .With the developing process, the exposed portions 213 and 214 of thephotoresist 211 are removed.

Then, an etching process is performed as illustrated in J of FIG. 21 .With the etching process, the portion excluding the portion masked bythe photoresist 211 is etched, and a part of the first member 111B isprocessed. With the process, the 30 reflectors having different heightsin the respective sub pixels 100 are formed, and the anode electrodes121R and 121G on the first member 111A are exposed.

Then, a resist peeling process is performed as illustrated in K of FIG.21 . With the resist peeling process, the photoresist 211 is peeled off.

Then, a vapor deposition process and a CVD film forming process areperformed as illustrated in L of FIG. 21 . With the vapor depositionprocess, a layer 141 including an organic layer and a cathode electrodelayer (formed of a transparent material such as ITO, for example) and aprotective film 142 are formed on the surface of the anode electrodes121R and 121G and the first member 111B formed on the first member 111A.Further, the organic layer emits light between the anode electrode andthe cathode electrode layer. For example, it is desirable that theorganic layer emit white light. Further, for example, an insulatingmaterial, a conductive material, or the like can be used as a materialof the protective film 142.

Then, a planarizing process is performed as illustrated in M of FIG. 22. With the planarizing process, a second member 151 is embedded andplanarized. Further, for example, a resin such as an acrylic resin, apolyimide resin, a silicon resin, or the like can be used as a materialof the second member 151.

As described above, after the layer 141 including the organic layer andthe cathode electrode layer and the protective film 142 are formed, thesecond member 151 is further formed, so that the light reflecting layer(reflector structure) including the first member 111 (111B) and thesecond member 151 is formed.

Then, a color filter forming process is performed as illustrated in N ofFIG. 22 . With the color filter forming process, color filters 131R and131G are formed on the planarized second member 151.

In the pixel 10 manufactured as described above, since the inclinedsurface 30 height of the reflector caused by the inclination of theinclined surface of the first member 111 is different for each sub pixel100, the respective sub pixels 100 differ in luminance, and thus it ispossible to improve the luminance of the specific sub pixel 100.

The first example of the manufacturing process has been described above.

(Second Example of Manufacturing Process)

Next, a flow of a second example of a top emission pixel manufacturingprocess according to an embodiment of the present technology will bedescribed with reference to FIGS. 23 to 27 .

Further, in the second example of the manufacturing process, for thesake of convenience of description, a flow of a process of manufacturingthe sub pixels 100R, 100G, 100W, and 100B as arbitrary sub pixels 100constituting the pixel 10 will be described.

Here, first, a dry processing process is performed as illustrated in Aof FIG. 23 . With the dry processing process, anode electrodes 121R,121G, 121W, and 121B are formed on a first member 111A. Further, forexample, SiO₂ or the like can be used as a material of the first member111A. Further, a reflective material such as Al, Cu or the like can beused as the material of the anode electrode 121.

Next, a CVD film forming process is performed as illustrated in B ofFIG. 23 . With the CVD film forming process, a first member 111B isformed on the anode electrodes 121R, 121G, 121W, and 121B formed on thefirst member 111A. Further, for example, P—SiO or the like can be usedas a material of the first member 111B.

Next, a resist coating process is performed as illustrated in C of FIG.23 . With the resist coating process, the first member 111B is coatedwith a photoresist 311.

Then, an exposure process is performed as illustrated in D of FIG. 24 .With the exposure process, a surface of the photoresist 311 is exposedto light in a pattern form using a photomask 321, so that a patternincluding the exposed portion (an exposed portion 312) and an unexposedportion (a portion excluding the exposed portion 312) is formed.

Then, a developing process is performed as illustrated in E of FIG. 24 .With the developing process, the exposed portion 312 of the photoresist311 is removed.

Then, an etching process is performed as illustrated in F of FIG. 24 .With the etching process, the portion excluding the portion masked bythe photoresist 311 is etched, and a part of the first member 111B isprocessed.

Then, a resist coating process is performed as illustrated in G of FIG.25 . With the resist applying process, the processed portion of thefirst member 111B is coated with the photoresist 311.

Next, an exposure process is performed as illustrated in H of FIG. 25 .With the exposure process, a surface of the photoresist 311 is exposedto light in a pattern form using a photomask 331, so that a patternincluding the exposed portions (exposed portions 313, 314, 315, and 316)and an unexposed portion (a portion excluding the exposed portions 313,314, 315, and 316) is formed.

Then, a developing process is performed as illustrated in I of FIG. 25 .With the developing process, the exposed portions 313, 314, 315, and 316of the photoresist 311 are removed.

Then, an etching process is performed as illustrated in J of FIG. 26 .With the etching process, the portion excluding the portion masked bythe photoresist 311 is etched, and a part of the first member 111B isprocessed. With the process, the reflectors having different heights inthe respective sub pixels 100 are formed, and the 30 anode electrodes121R, 121G, 121W, and 121B on the first member 111A are exposed.

Then, a resist peeling process is performed as illustrated in K of FIG.26 . With the resist peeling process, the photoresist 311 is peeled off.

Then, a vapor deposition process and a CVD film forming process areperformed as illustrated in L of FIG. 26 . With the vapor depositionprocess, a layer 141 including an organic layer and a cathode electrodelayer (formed of a transparent material such as ITO, for example) and aprotective film 142 are formed on the surface of the anode electrodes121R, 121G, 121W, and 121B and the first member 111B formed on the firstmember 111A. Further, the organic layer emits light between the anodeelectrode and the cathode electrode layer. For example, it is desirablethat the organic layer emit white light. Further, for example, aninsulating material, a conductive material, or the like can be used as amaterial of the protective film 142.

Then, a planarizing process is performed as illustrated in M of FIG. 27. With the planarizing process, a second member 151 is embedded andplanarized. Further, for example, a resin such as an acrylic resin, apolyimide resin, a silicon resin, or the like can be used as the secondmember.

As described above, after the layer 141 including the organic layer andthe cathode electrode layer and the protective film 142 are formed, thesecond member 151 is further formed, so that the light reflecting layer(reflector structure) including the first member 111 (111B) and thesecond member 151 is formed.

Then, a color filter forming process is performed as illustrated in N ofFIG. 27 . With the color filter forming process, color filters 131R,131G, and 131B are formed on the planarized second member 151.

In the pixel 10 manufactured as described above, since the inclinedsurface height of the reflector caused by the inclination of theinclined surface of the first member 111 is different for each sub pixel100, the respective sub pixels 100 differ in luminance, and thus it ispossible to improve the luminance of the specific sub pixel 100.

The second example of the manufacturing process has been describedabove.

2. Modified Example

In the above-described embodiments, the pixel 10 is described as beingthe WRGB pixel, that is, including the four sub pixels 100R, 100G, 100B,and 100W, but the configuration of the sub pixel 100 is not limitedthereto.

For example, the pixel 10 may not include the sub pixel 100W and mayinclude three sub pixels 100R, 100G, and 100B. Further, for example, asub pixel 100 of another color having high visibility equal to that ofwhite (W) may be used instead of the white (W) sub pixel 100W. Further,in the pixel 10, the arrangement order of a plurality of sub pixels 100may be an arbitrary order that differs for each color.

Further, in the first and second embodiments, the inclined surfaceheight of the reflector 112 is adjusted for each sub pixel 100, whereasin the third embodiment, the position of the anode electrode 121 side isadjusted for each sub pixel 100, but the adjustments may be performed atthe same time. In other words, in the pixel 10, both the inclinedsurface height of the reflector 112 and the position on the anodeelectrode 121 side may be adjusted for each sub pixel 100.

Further, a material and a thickness of each layer, a film formingmethod, a 25 film forming conditions, and the like described in theabove embodiments are not limited to the above description, and othermaterials and thicknesses, or other film forming methods, and other filmforming conditions may be used. Further, in the above-describedembodiments and the like, the configuration of the organic lightemitting element 101 has been specifically described, but it is notnecessary to include all the layers, and another layer may be furtherincluded.

Further, in the above-described embodiments, the configuration of theactive matrix type display element (display device) has been described,but the present technology can be also applied to a passive matrix typedisplay element (display device). Furthermore, the configuration of thepixel drive circuit for active matrix driving is not limited to thatdescribed in the above embodiments, and a capacitive element, atransistor, or the like may be added if necessary. In this case, inaddition to the signal line drive circuit 21 (FIG. 1 ) and the scan linedrive circuit 22 (FIG. 1 ) described above, a necessary drive circuitmay be appropriately added with a change in the pixel drive circuit.

3. Examples of Electronic Device (Example of Single-Lens Reflex Camera)

FIG. 28 illustrates an example of an external appearance of asingle-lens reflex camera (a lens interchangeable single-lens reflextype digital camera) as an electronic device (an imaging apparatus) towhich the display element to which an embodiment of the presenttechnology is applied is applied.

As illustrated in A of FIG. 28 , the single-lens reflex camera includes,for example, an interchangeable photographing lens unit (interchangeablelens) 412 installed on a front right side of a camera body (camera body)411 and a grip portion 413 installed on a front left side and gripped bya photographer.

Further, as illustrated in B of FIG. 28 , a monitor 414 is installedsubstantially at a central portion of a rear surface of the camera body411. A viewfinder (eyepiece window) 415 is installed above the monitor414. By looking into the viewfinder 415, the photographer can visuallyrecognize a light image of a subject guided from the photographing lensunit 412 and decide a composition.

This viewfinder 415 is constituted by the display element (displayelement 1) to which an embodiment of the present technology describedabove is applied.

(Example of Head Mounted Display)

FIG. 29 illustrates an example of an external appearance of a headmounted display (HMD) as an electronic device to which the displayelement to which an embodiment of the present technology is applied isapplied.

As illustrated in A of FIG. 29 , the head mounted display includes, forexample, ear hook portions 512 worn on a head of a user formed on bothsides of a glasses type display unit 511. The display unit 511 isconstituted by the display element (display element 1) to which anembodiment of the present technology is applied.

For example, the user wearing the head mounted display of A of FIG. 29on the head can view a virtual reality (VR) video displayed on thedisplay unit 511.

Further, A of FIG. 29 illustrates an example of a non-transmissive typehead mounted display completely covering the eyes of the user, but adisplay unit 521 of a transmissive type (for example, video transmissivetype or the like) head mounted display may be constituted by the displayelement (display element 1) to which an embodiment of the presenttechnology is applied as illustrated in B of FIG. 29 .

For example, the user wearing the head mounted display of B of FIG. 29on the head can view an augmented reality (AR) image displayed on thedisplay unit 521.

Other Examples

Further, in FIGS. 28 and 29 , the single-lens reflex camera and the headmounted display are illustrated as the electronic devices to which thedisplay element to which an embodiment of the present technology isapplied is applied, but the display element to which an embodiment ofthe present technology is applied may be applied to an electronic devicesuch as, for example, a smartphone, a television receiver, a personalcomputer, a video camera, a mobile phone, a game machine, a wearabledevice, or the like.

Further, the embodiments of the present technology are not limited tothe above-described embodiments, and various modifications can be madewithin the scope not departing from the gist of the present technology.

According to an embodiment of the present technology, there is provideda display element, including: a display region including pixels arrangedin a two-dimensional form, each of the pixels including a plurality ofsub pixels. In each pixel, a height of a light reflecting portion withrespect to a light emitting portion is adjusted for each sub pixel.

In a display element according to an embodiment of the presenttechnology, a display region including pixels arranged in atwo-dimensional form is provided, each of the pixels including aplurality of sub pixels. In each pixel, a height of a light reflectingportion with respect to a light emitting portion is adjusted for eachsub pixel.

According to an embodiment of the present technology, there is providedan electronic device including a display element including a displayregion including pixels arranged in a two-dimensional form, each of thepixels including a plurality of sub pixels. In each pixel, a height of alight reflecting portion with respect to a light emitting portion isadjusted for each sub pixel.

An electronic device according to an embodiment of the presenttechnology is equipped with a display element in which a display regionincluding pixels arranged in a two-dimensional form is provided, each ofthe pixels including a plurality of sub pixels. In each pixel, a heightof a light reflecting portion with respect to a light emitting portionis adjusted for each sub pixel.

Further, the display element or the electronic device according toembodiments of the present technology may be an independent device or aninternal block constituting one device.

Additionally, the present technology may also be configured as below.(1)A display element, including:

-   -   a display region including pixels arranged in a two-dimensional        form, each of the pixels including a plurality of sub pixels,    -   in which, in each pixel, a height of a light reflecting portion        with respect to a light emitting portion is adjusted for each        sub pixel.        (2)        The display element according to (1), in which a height of an        inclined surface of the light reflecting portion in a stacking        direction is adjusted for each sub pixel.        (3)        The display element according to (2), in which the height of the        inclined surface of the light reflecting portion is different        for each sub pixel.        (4)        The display element according to (2), in which the height of the        inclined surface of the light reflecting portion is different        only in a specific sub pixel among the plurality of sub pixels.        (5)        The display element according to (1), in which a position of the        light emitting portion in a stacking direction is adjusted for        each sub pixel.        (6)        The display element according to (5), in which the position of        the light emitting portion is different for each sub pixel.        (7)        The display element according to (5), in which the position of        the light emitting portion is different only in a specific sub        pixel among the plurality of sub pixels.        (8)        The display element according to any one of (1) to (7), in which        a height of an inclined surface of the light reflecting portion        is adjusted in accordance with an angle of the inclined surface        of the light reflecting portion and a width of a light emitting        part of the light emitting portion.        (9)

The display element according to any one of (1) to (8), in which eachpixel includes a first sub pixel, a second sub pixel, and a third subpixel that emit three basic colors of light and a fourth sub pixel thatemits a non-basic color of light.

(10)The display element according to (9), in which the basic colors of lightinclude red light, green light, and blue light, and the non-basic colorof light is white light.(11)The display element according to any one of (1) to (10),

-   -   in which the sub pixel is a pixel including a light emitting        element which emits light as the light emitting portion, and    -   the light emitting element includes an electrode and an organic        layer including a light emitting layer.        (12)        An electronic device including    -   a display element including    -   a display region including pixels arranged in a two-dimensional        form, each of the pixels including a plurality of sub pixels,    -   in which, in each pixel, a height of a light reflecting portion        with respect to a light emitting portion is adjusted for each        sub pixel.        (13)        A display element, comprising:    -   a display region including a plurality of pixels arranged in a        two-dimensional form, the plurality of pixels including a first        pixel, a second pixel and a third pixel,    -   a first light reflecting portion located between the first pixel        and the second pixel, and a second light reflecting portion        located between the second pixel and the third pixel,    -   wherein a height of the first light reflecting portion and a        height of the second light reflecting portion with respect to a        light emitting portion of the plurality of pixels are different.        (14)        The display element according to (13), wherein the height of the        first light reflecting portion and the height of the second        light reflecting portion are different with respect to a common        plane in a stacking direction.        (15)        The display element according to (13), wherein a position of the        first light reflecting portion and a position of the second        light reflecting portion in a stacking direction relative to a        position of a light emitting portion of the plurality of pixels        are different.        (16)        The display element according to (13), wherein the height of        each light reflecting portion is a length along which a light        reflecting surface of that light reflecting portion extends in a        stacking direction.        (17)        The display element according to (13), wherein each of the        first, second and third pixels emits either one of the three        basic colors of light or a non-basic color of light.        (18)        The display element according to (17), wherein the basic colors        of light include red light, green light, and blue light, and the        non-basic color of light is white light.        (19)        The display element according to (13),    -   wherein each pixel is a pixel including a light emitting element        which emits light as the light emitting portion, and    -   the light emitting element includes an electrode and an organic        layer including a light emitting layer.        (20)        An electronic device comprising    -   a display element, the display element comprising    -   a display region including a plurality of pixels arranged in a        two-dimensional form, the plurality of pixels including a first        pixel, a second pixel and a third pixel,    -   a first light reflecting portion located between the first pixel        and the second pixel, and    -   a second light reflecting portion located between the second        pixel and the third pixel,    -   wherein a height of the first light reflecting portion and a        height of the second light reflection portion with respect to a        light emitting portion of the plurality of pixels are different.        (21)        A bottom emission organic electroluminescence, EL, display        element, comprising:    -   a display region including a plurality of pixels arranged in a        two-dimensional form,    -   the plurality of pixels including a first pixel, a second pixel        and a third pixel,    -   a first light reflecting portion located between the first pixel        and the second pixel, and    -   a second light reflecting portion located between the second        pixel and the third pixel,    -   wherein a height of the first light reflecting portion and a        height of the second light reflecting portion with respect to a        light emitting portion of the plurality of pixels are the same.        (22)        The display element according to (21), wherein the height of        each light reflecting portion is a length along which a light        reflecting surface of that light reflecting portion extends in a        stacking direction.        (23)        The display element according to (21), wherein each of the        first, second and third pixels emits either one of the three        basic colors of light or a non-basic color of light.        (24)        The display element according to (23), wherein the basic colors        of light include red light, green light, and blue light, and the        non-basic color of light is white light.        (25)        The display element according to (21), wherein    -   each pixel is a pixel including a light emitting element which        emits light as a light emitting portion, and    -   the light emitting element includes an electrode and an organic        layer including a light emitting layer.        (26)        An electronic device comprising a bottom emission organic EL        display element, the bottom emission organic EL display element        comprising:    -   a display region including a plurality of pixels arranged in a        two-dimensional form,    -   the plurality of pixels including a first pixel, a second pixel        and a third pixel,    -   a first light reflecting portion located between the first pixel        and the second pixel, and    -   a second light reflecting portion located between the second        pixel and the third pixel,    -   wherein a height of the first light reflecting portion and a        height of the second light reflecting portion with respect to a        light emitting portions of the plurality of pixels are the same.

REFERENCE SIGNS LIST

-   -   1 display element    -   10 pixel    -   11 substrate    -   21 signal line drive circuit    -   22 scan line drive circuit    -   23 display region    -   31 signal line    -   32 scan line    -   33 pixel drive circuit    -   100, 100R, 100G, 100B, 100W sub pixel    -   101, 101R, 101G, 101B, 101W organic light emitting element    -   111 first member    -   112, 112R, 112G, 112B, 112W reflector    -   121, 121R, 121G, 121B, 121W anode electrode    -   131, 131R, 131G, 131B color filter    -   141 layer    -   142 protective film    -   151 second member

1. (canceled)
 2. A bottom emission display element comprising: a displayregion including a plurality of pixels arranged in a two-dimensionalarray, the plurality of pixels including a first pixel, a second pixeland a third pixel, a first light reflecting portion located between thefirst pixel and the second pixel, and a second light reflecting portionlocated between the second pixel and the third pixel, wherein a heightof the first light reflecting portion and a height of the second lightreflecting portion are the same with respect to a light emitting portionof at least one of the plurality of pixels.
 3. The bottom emissiondisplay element according to claim 2, wherein the height of the firstlight reflecting portion is a length along which a light reflectingsurface of the first light reflecting portion extends in a stackingdirection.
 4. The bottom emission display element according to claim 2,wherein the first, second and third pixels respectively emit one of redlight, green light, blue light or white light.
 5. The bottom emissiondisplay element according to claim 2, wherein each of the first, secondand third pixels includes a light emitting element which emits light asa light emitting portion, the light emitting element including anelectrode and an organic layer including a light emitting layer.
 6. Anelectronic device comprising a bottom emission display element accordingto claim
 2. 7. The electronic device according to claim 6, wherein theheight of the first light reflecting portion is a length along which alight reflecting surface of the first light reflecting portion extendsin a stacking direction.
 8. The electronic device according to claim 6,wherein the first, second and third pixels respectively emit one of redlight, green light, blue light or white light.
 9. The electronic deviceaccording to claim 6, wherein each of the first, second and third pixelsincludes a light emitting element which emits light as a light emittingportion, the light emitting element including an electrode and anorganic layer including a light emitting layer.